Step 1: What you need

Download the Workshop addon "A Quied Drink"
be sure you have installed the "Vermintide Mod Framework"
Ignore Step 2 if you know what the order should look like

Step 2: Mods Order

Open the Vermintide 2 Launcher and Check the mods order
1.Vermintide Mod Framework
2.A Quied Drink

Step 3: Glitch start

Start the game in Custom Realm first.
Ingame, choose the map under "Own Game" and start it once.
You don't need to play the whole map, just close the game

Final Step: Lets play

Now you only need to start your game in the official realm and under "own game" you should still find the map "a quiet drink".

Have fun drinking!